JP3076743B2 - Follow-up operation control device for hydraulic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking operation control method and a tracking operation control device for hydraulic equipment. More specifically, in order to make the stroke or internal pressure of a hydraulic actuator such as a cylinder or a ram having a variable stroke and a hydraulic device such as a pressure vessel having a variable internal pressure such as a pressure tank follow a target pattern. To a control method and a control device. As an example of the above-mentioned hydraulic equipment, it was used in the synthesis of diamond and cubic boron nitride, and was charged in the ultra-high pressure space of an ultra-high pressure generator used to test the deformation characteristics of materials under ultra-high pressure There is a driving cylinder or ram for a piston body that applies a uniaxial compressive force to the sample body. There are also a hydraulic press and a ram of a powder press molding machine. In the cylinder for driving the piston body for the deformation characteristic test, for example, the stroke is changed by about 1 to 3 mm or the pressure is set to 100 to 30 for one month.
Accurate control over an extremely long time, such as changing about 0 kgf / cm ^2, is required.

[0002]

2. Description of the Related Art An example of a conventional control device for causing a hydraulic cylinder to follow a target pattern is disclosed in Japanese Patent Application Laid-Open No. 1-18.
No. 8781 discloses this. This control device, as shown in FIG.
A plurality of (three) valves 104a, 104b, 104c are interposed in series in 103, an accumulator 105a is provided between the valves 104a and 104b, and an accumulator 105b is provided between the valves 104b and 104c. . By arbitrarily combining and opening and closing two of the three valves, and by strictly controlling the opening and closing operation time, the amount of pressure oil discharged from the cylinder 108 is controlled, so that the hydraulic cylinder 108 can operate for a long time. Pressure reduction control can be performed.

[0003]

However, the above-mentioned conventional apparatus has the following disadvantages. First, since it has only a function of discharging pressure oil, only pressure reduction control can be applied, and pressure increase control cannot be performed. Therefore, it cannot be used for testing the deformation characteristics of a substance under ultra-high pressure. Further, when the volume of the pressure device is relatively large, that is, when the compression volume is large, the control can be performed with high accuracy, but the accuracy decreases as the pressure device becomes smaller. This is because, when the volume of the cylinder 108 is small, all the liquid in the compression volume within the volume between any two valves is discharged, so that the ratio of the discharge amount to the volume of the cylinder 108 increases, and the accuracy is low. Because it becomes.

[0004] The present invention has been made in view of the above circumstances, it is capable of boosting and depressurizing control of the hydraulic equipment, extremely long periods of time with greatly improved trackability with respect to the target pattern of pressure and stroke
And to provide a barrel following operation control method and apparatus.

[0005]

SUMMARY OF THE INVENTION The following operation control system for a hydraulic device of claim 1, follow-up operation control instrumentation for follow the internal pressure or the stroke of the hydraulic equipment to the target pattern
A location, a flow passage connected to the oil chamber of the hydraulic equipment,
A check valve, a first on-off valve, a second on-off valve,
Accumulator, hydraulic pump and straw for the hydraulic device
Pressure detector or the pressure in the oil chamber of the hydraulic equipment.
A pressure detector for detecting a force, and a pressure of the accumulator.
A pressure detector for detecting a force, and a position detector for the hydraulic device
Or pressure detector and a pressure test of the accumulator
The operation of the hydraulic pump and the
A control device for controlling the opening and closing operations of the first and second on-off valves
And the pressure of the accumulator is controlled by the hydraulic device.
Keep the pressure slightly higher than the pressure and close the first on-off valve.
In this state, the second on-off valve is opened, and the first and second on-off valves are opened.
Pressure in the flow path of the hydraulic device is higher than that of the hydraulic device,
Close the on-off valve and open the first on-off valve to open the hydraulic device.
Supplying a slightly higher pressure to the oil chamber
To increase the pressure to the target value for an extremely long time
Characterized in that to follow. Follow-up operation control system for a hydraulic apparatus of claim 2, there is provided a follow-up operation control device for tracking the internal pressure or the stroke of the hydraulic equipment with respect to the target pattern, the flow path connected to the oil chamber of the hydraulic equipment ,
First open / close valve, accumulator, second open
Closing the valve and connecting the accumulator to the flow path;
A third on-off valve interposed in the oil connection, and the accumulator
A hydraulic pump for supplying hydraulic oil to the
A position detector for detecting a troke or an oil chamber of the hydraulic device
A pressure detector for detecting the pressure inside the accumulator;
Pressure detector for detecting the pressure of the
Detector or pressure detector and pressure of said accumulator
Drive of the hydraulic pump based on the detection data of the force detection
And a control for controlling the opening and closing operations of the first, second and third on-off valves.
Controlling the pressure of the accumulator
Keep the pressure of the hydraulic equipment slightly lower and open the first and second
With the valve closed, the third on-off valve is opened to open the first and first valves.
The pressure in the flow path between the two on-off valves is made lower than that of the hydraulic device,
Next, the first on-off valve is opened and the hydraulic pressure is released from the oil chamber of the hydraulic device.
By discharging this slightly and repeating this cycle
It is characterized in that the target value is followed by the decompression for a long time . The follow-up control device according to claim 3 is configured to control the internal pressure of the hydraulic device or
Is to make the stroke follow the target pattern
A follow-up operation control device, comprising: a pressure generating unit including two open / close valves and an accumulator connected to a pump in a first flow path connected to the hydraulic device; The device and a second flow path connected to the hydraulic device, two on-off valves are connected in series, and a pressure generating unit composed of an accumulator connected to a pump is connected to the third on-off valve between the two on-off valves. And a pressure-reducing operation control device connected via the on-off valve. Follow-up control apparatus according to claim 4, the target pattern of internal pressure or stroke of the hydraulic equipment
Tracking operation control device
An on-off valve and a three-port three-position switching valve sequentially disposed in a flow path connected to the hydraulic device, an accumulator connected to one port of the switching valve, and a tank connected to the other port And connected to the accumulator
Pump and position detection for detecting the stroke of the hydraulic equipment
Pressure detector for detecting the pressure in the oil chamber of the
And a pressure detector for detecting the pressure of the accumulator.
And a position detector or a pressure detector of the hydraulic device.
And pressure data of the accumulator
The drive of the hydraulic pump, the on-off valve and the switching valve
A control device for controlling the opening and closing operation of the accumulator.
The pressure of the humidifier is slightly lower than the pressure of the hydraulic equipment.
Keep it high and supply it to the oil chamber of the hydraulic equipment to raise the pressure
Control the pressure of the accumulator to the hydraulic equipment
Oil chamber of the hydraulic device, slightly lower than the pressure
And control the pressure reduction operation . The tracking control device according to claim 5, wherein the internal pressure of the hydraulic equipment or the straw
Movement control system to make the robot follow the target pattern
A flow path connected to an oil chamber of the hydraulic device.
A first on-off valve, an accumulator, and a
2 Connect the on-off valve and the accumulator to the flow path
A third on-off valve interposed in the connecting oil passage;
A hydraulic pump for supplying hydraulic oil to the
Position detector for detecting stroke or oil for the hydraulic device
A pressure detector for detecting the pressure in the room;
A pressure detector for detecting the pressure of the
Position detector or pressure detector and the accumulator
The hydraulic pump is driven based on the detection data of the pressure detection.
And the opening and closing operations of the first, second and third on-off valves.
And a controller for controlling the pressure of the accumulator.
Keep the oil pressure slightly higher than the hydraulic
Supply to the oil chamber of the pressure equipment to control the boost operation,
Murator pressure slightly lower than the hydraulic equipment pressure
Compression and discharge from the oil chamber of the hydraulic equipment
It is characterized by controlling .

[0006] follow-up control apparatus according to claim 6 is the invention of claim 4, wherein the high-pressure pressure generating section comprising a high-pressure accumulator connected to the pump to one port of the three-port three-position switching valve, the pump The low-pressure accumulator connected to the low-pressure accumulator is selectively connected via a flow path selection mechanism, and another port of the switching valve is connected to a tank. According to a seventh aspect of the present invention, in the tracking control device according to the fifth aspect , the first and second
A high-pressure pressure generator composed of a high-pressure accumulator with a pump connected to the flow path between the on-off valves and a low-pressure pressure generator composed of a low-pressure accumulator with the pump connected selectively via a flow path selection mechanism. It is characterized by being connected.

[0007] In inventions of claims 1, first, the pressure oil in the volume between the second on-off valve had been held in a state of applying pressure, the hydraulic pressure alone difference between between hydraulic equipment and the on-off valve It is allowed to flow into the hydraulic machine <br/> device. Having thus vary the internal pressure and the stroke of the hydraulic equipment at a constant volume of hydraulic flow and pressure difference, the pressure difference allows precision control so static element, high precision pressure and stroke thus hydraulic equipment And the accuracy reaches several tens of times that of the conventional device. In addition, even when the hydraulic flow rate is small, the pressure control can be performed with high accuracy regardless of the flow rate, so that the tracking accuracy over an extremely long time can be maintained high. The inventions of claims 2, first, between the second on-off valve
Keeping the volume pressurized with hydraulic pressure,
The hydraulic pressure is converted to hydraulic equipment by the pressure difference between the hydraulic equipment and the on-off valve.
Let it drain. In this way, the pressure difference and the fixed amount of hydraulic flow rate
Changes the internal pressure and stroke of the pressure equipment, but the pressure difference is static.
High precision control is possible because
The pressure and stroke of pressure equipment can be controlled with high precision,
The degree reaches several tens of times that of the conventional device. Also, the hydraulic flow rate
Even when the pressure is small, the pressure control is highly accurate regardless of the flow rate
So that the tracking accuracy for an extremely long time can be maintained at a high level.
Wear. According to the third aspect of the present invention, since there are two systems of control devices for the pressure increasing operation and the pressure reducing operation, the pressure reducing operation of the hydraulic device and the contraction stroke operation of the telescopic device are also performed by the pressure increasing of the hydraulic device and the extension of the telescopic device. Stroke operation can be easily performed.
In addition, since it is controlled by a static element called pressure difference,
High-precision tracking control over time is possible. Claim 4
In the invention, the step-up control for supplying hydraulic pressure to the hydraulic equipment pressure between off valve and switching valve to be higher than the internal pressure of the hydraulic equipment, oil
Pressure reduction control for discharging the oil pressure in the hydraulic equipment to lower than the internal pressure of the pressure device can be freely by the pressure adjustment to lower or raise the pressure of the accumulator by driving the pump. In the invention of claim 5, the step-up control for supplying high-pressure hydraulic pressure to hydraulic equipment pressure between the two on-off valve to be higher than the internal pressure of the hydraulic equipment, the hydraulic pressure in hydraulic equipment and lower than the internal pressure of the hydraulic equipment The pressure reduction control for discharging can be freely performed by adjusting the pressure of the accumulator to increase or decrease by driving the pump.

According to the sixth aspect of the present invention, the high-pressure accumulator and the low-pressure accumulator are separately provided, and the high-pressure hydraulic pressure and the low-pressure hydraulic pressure can be selectively supplied between the on-off valve and the switching valve by the flow path selecting mechanism. The pressure increase control and the pressure decrease control can be performed without adjusting the pressure of the accumulator. In the invention according to claim 7, the high-pressure accumulator and the low-pressure accumulator are separately provided, and the high-pressure oil pressure and the low-pressure oil pressure can be selectively supplied between the two on-off valves by the flow path selection mechanism. Both the boost control and the depressurization control can be performed without adjustment.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. First, an ultra-high pressure generator to which the control method and the control device of the present invention are applied will be described with reference to FIG. 16. 51 is an upper anvil, 52 is a lower anvil, and a pair of upper and lower anvils 51 and 52 Also has a tapered quadrangular truncated pyramid-shaped tip, and is arranged such that the end faces of the tips face each other. Reference numeral 53 denotes a side anvil disposed at an intermediate position between the anvils 51 and 52, similarly to the anvils 51 and 52, and having a tapered quadrangular truncated pyramid-shaped tip. The anvil 53 is disposed in the front, rear, left and right directions, and an ultra-high pressure generation chamber 54, which is a space for accommodating an object to be compressed, is formed by the end surfaces of the distal ends thereof and the distal end surfaces of the pair of upper and lower anvils 51, 52. You. Reference numeral 2 denotes an upper cylinder (or ram) for driving the piston body 1 described later, and reference numeral 56 denotes a lower cylinder (or ram) for driving the lower anvil 52. The pair of anvils 51 and 52 and the pair of upper and lower cylinders (or rams)
The reference numerals 2 and 56 are attached to the press frame 57 coaxially, each centered on the axis y. In addition, in the illustrated example, one of the pair of anvils 51 and 52 is an upper anvil.
A piston hole is formed in the shaft 51 concentrically with the axis y, and the piston body 1 is inserted. The piston body 1 compresses the object to be compressed under an ultra-high pressure to test the deformation characteristics of the substance under the ultra-high pressure. In accordance with the present invention, the cylinder (or ram) 2 for driving the piston body 1 is controlled to follow its internal pressure and expansion / contraction stroke. In this case, the piston body 1 is moved at a very low speed of about 1 × 10 ⁻² mm / H, for example.
It is necessary to drive for about one month. Note that the stroke does not need to be continuously changed, and may be driven in a stepwise manner as shown in FIG. In this case, it is desired that the stroke amount (ΔL) in one operation be as small as possible.

Next, embodiments of the following operation control apparatus according to the present invention will be described. (First Embodiment) FIG. 1 is claimed
Ru cruise control system der boosting operation according to the invention of claim 1. oil
On- off valves 4 and 5 at two ports and two positions are interposed in series in an oil passage 30 between an oil chamber of the cylinder 2 as a pressure device and the hydraulic pump 8, and between the on-off valve 5 and the hydraulic pump 8. An accumulator 6 is interposed. 3 is a cylinder 2 pressure detector,
7 is a pressure detector of the accumulator 6, and 14 is a position detector for detecting the stroke of the piston body 1. In addition, between the cylinder 2 and the opening and closing valve 4, preferably preferably provided a check valve 31 for preventing leakage. The drive of the hydraulic pump 8 and the opening and closing of the on-off valves 4 and 5 are controlled by a control device using a microcomputer or the like, and follow the target pattern based on the detection data of the pressure detectors 3 and 7 and the position detector 14. Controlled. In the figure, V0 is the amount of oil (volume) in the cylinder 2, P0 is the internal pressure of the cylinder 2, P1 is the pressure of the accumulator 6, and the apparatus of FIG. It is set higher than the internal pressure P0 of the cylinder 2.

In this device, when the on-off valves 4 and 5 are opened and closed as shown in FIG. 2, the boost control is performed. That is,
The on-off valve 5 is opened, the pressure oil in the accumulator 6 is supplied to the oil passage between the on-off valves 4 and 5, and is maintained at a pressure P1 higher than the cylinder internal pressure P0, and then the on-off valve 5 is closed. When the cylinder 4 is opened, the pressure oil of the pressure P1 is supplied into the cylinder 2 and the internal pressure P0 of the cylinder 2 is increased or the piston 1
Is changed in the extension direction. In this case, the supply amount of the pressure oil to the cylinder 2 and the pressure increase amount of the cylinder 2 depend on the differential pressure (P1-P0), so that the supply amount of the pressure oil can be minutely controlled.

When calculating how much the stroke of the cylinder 2 increases by one opening / closing operation of the on-off valves 4 and 5,
It is as follows. A: cross-sectional area of cylinder L0: oil level in cylinder V1: oil amount (volume) between on-off valves 4, 5 P1: pressure of accumulator 6 (opening of on-off valve 5) (Pressure immediately after valve opening) β: Compression rate of hydraulic oil Δp: ΔL is 0 during one opening / closing operation of on / off valves 4 and 5
(In this case, the piston body 1 does not move.) ΔL......
(In this case, the pressure in the cylinder 2 does not change.) The rising stroke ΔL of the cylinder becomes maximum when P0 is constant, and can be calculated by the following equation. ΔL = β (P1−P0) V1 / A (1) where β = 12 × 10 ⁻⁵ cm ² / kgf, A = 100 cm ² (φ1
1.3), V1 = 5cc, P0 = 200kgf / cm 2, P1 = 2
If it is 05kgf / cm ² , ΔL = 0.0003mm ……………
(1) '. Conversely, the rise in the internal pressure P0 of the cylinder 2
When ΔL is 0, it becomes maximum and can be calculated by the following equation. ΔP = (P0V0 + P1V1) / (V0 + V1) -P0 (2) where L0 = 20 cm = (200.times.2000 + 205.times.5)
/(2000+5)-200=0.012kgf/cm ² ………………
... (2) ′. In practice,
This is an intermediate value between (1) 'and (2)'.

When the above-described one cycle is repeated, the internal pressure P0 of the cylinder 2 increases stepwise as shown in FIG. ΔPmax is the accumulator pressure P1 and cylinder 2
ΔPmin is the minimum differential pressure between the internal pressures P0. When the differential pressure becomes minimum, the pump 8 is driven to increase the pressure P1 of the accumulator 6. The symbol u indicates the pressure increase of the accumulator 6 by driving the pump 8. By controlling the opening and closing of the on-off valves 4 and 5 and the driving of the hydraulic pump 8 by the control device as described above, the internal pressure P0 of the cylinder 2 can be brought close to the target pattern. The target pattern in this case can be set arbitrarily.

The control method according to the present invention includes pressure control and stroke control (position control). In each case, the actual value falls within the control bandwidth with respect to the target value as shown in FIG. The maximum differential pressure ΔPmax and the minimum differential pressure Δ
Pmin and time T between each control cycle may be set for automatic control. In the case of stroke control, the actual position may be detected by the position detector 14 and feedback control may be performed.

[0015](2nd Embodiment)  Figure 4According to the invention of claim 2Tracking control device for pressure reduction operation
InYou.In the oil passage 33 between the oil chamber of the cylinder 2 and the tank 32
Two on-off valves 9 and 10 at 2 ports and 2 positions are interposed in series,
The accumulator 12 is connected between the on-off valves 9 and 10 by the oil passage 34
The third open / close valve 11 is interposed in the oil passage 34,
The hydraulic pump 8 is connected to the pump 12 via an oil passage 35.
The pressure detectors 3, 13 and the position detector 14 are the same as those in the apparatus shown in FIG.
It is like. Since this device performs pressure reduction control,
The pressure P2 of the generator 12 is set lower than the cylinder pressure P0.
Have been.

In this control device, as shown in FIG. 5, when the on-off valves 9, 10, and 11 are opened and closed, pressure reduction control is performed. That is, the on-off valve 11 is opened and the accumulator 12
Pressure oil in the cylinder 2 is supplied between the on-off valves 9 and
The state of pressure P2 lower than 0 is maintained. Then on-off valve 9
Is opened, the pressure oil in the cylinder 2 flows into the oil passage between the on-off valves 9 and 10 due to the differential pressure (P0-P2) between the cylinder 2 internal pressure P0 and the inter-valve pressure P2, and the cylinder 2 internal pressure P0 decreases. . In this case, the amount of outflow from the cylinder 2 and the amount of pressure reduction of the cylinder 2 depend on the differential pressure, so that the discharge of pressurized oil can be minutely controlled. After this, the on-off valve 10
Is opened, the pressure oil between the on-off valves 9 and 10 is discharged to the tank. The pressure of the accumulator 12 can be set by driving the hydraulic pump 8. The above is one cycle of the pressure reduction control, and the time T is taken between the next control cycles.

FIG. 6 is a time pressure diagram when the above control cycle is repeatedly performed. ΔPmax is the maximum differential pressure between the cylinder internal pressure P0 and the pressure P2 of the accumulator 12, and ΔPmin is the minimum differential pressure. FIG. 6A shows a case where the pressure between the on-off valves 9 and 10 is opened and closed by opening and closing the on-off valves 10 and 11 to increase the differential pressure (indicated by d) from time to time, and FIG. By driving the hydraulic pump 8, the accumulator 12
Has been performed (indicated by the symbol u).

[0018](Third embodiment) FIG. 7 shows an embodiment of the third aspect of the present invention. More than
As described above, the boosting control can be performed by the apparatus of FIG.
Although pressure control can be performed, cylinder 2
To increase or decrease the pressure of the
I do. If the internal pressure of cylinder 2 drops,
When the internal pressure of the cylinder 2 rises, it is lowered.
You. Therefore, the control circuit of FIG.
And the control circuit of FIG. Figure 7 shows that
FIG. 1 is a circuit diagram of a tracking control device configured as described above, and reference numerals are used in FIG.
1 and FIG. 4, and a duplicate description will be omitted.
You. In the embodiment of FIG. 7, two accumulators are used.
7 and 12, each having a pressure higher than the internal pressure of the cylinder 2 (P
1) and low pressure (P2) pressure oil.
Of the operation of the on-off valves 4, 5 or the operation of the on-off valves 9, 10, 11
Simply select one of them, and freely increase or decrease pressure
There is an advantage that it can also be performed.

( Fourth Embodiment) FIG. 8 shows a fourth embodiment of the present invention. In the above-described embodiment, two control devices are provided. However, it is also possible to perform boost control and depressurization control with one device.
FIG. 8 shows an example of such a control device, in which an on-off valve 4 and a switching valve 15 at a 3-port 3 position are interposed in series in an oil passage 30 between the oil chamber of the cylinder 2 and the hydraulic pump 8, and switching is performed. The accumulator 6 and the hydraulic pump 8 are connected to the port a of the valve 15,
The port is connected to the tank 32 by an oil passage 36. Other configurations are the same as those of the control device of FIG.

In this follow-up control device, when performing the boost control, the pressure P1 of the accumulator 6 is set higher than the internal pressure P0 of the cylinder 2, and the on-off valve 4 is turned on in the order shown in FIG.
And the switching valve 15 is opened and closed. That is, a of the switching valve 15
When the port is connected to the oil passage 30 and the pressure oil of the accumulator 6 is supplied between the on-off valve 4 and the switching valve 15 to maintain the pressure higher than the internal pressure of the cylinder 2, then the on-off valve 4 is opened. High-pressure oil between the valves is supplied into the cylinder 2. By repeating this control operation, boost control can be performed.

When controlling the pressure reduction, the accumulator 6
Pressure P1 is lower than the internal pressure P0 of the cylinder 2,
The on-off valve 4 and the switching valve 15 are opened and closed in the order shown in FIG.
That is, the port a of the switching valve 15 is connected to the oil passage 30 to fill the pressure oil of the accumulator 6 between the on-off valve 4 and the switching valve 15, and then the on-off valve 4 is opened. Oil flows into the volume between the valves 4 and 15, which is on the low pressure side. As a result, when the internal pressure P0 of the cylinder 2 is reduced by a predetermined value, the port b of the switching valve 15 is connected to the oil passage 36, and the valves 4 and 15 are connected.
The pressure oil between them is discharged to the tank 32. Pressure reduction control can be performed by repeating this control operation.

When the internal pressure of the cylinder 2 is controlled to be constant by switching between the pressure increase control and the pressure reduction control as needed, for example, when changing from the pressure increase control to the pressure reduction control, the pressure P1 of the accumulator is increased after the pressure increase control is performed. What is necessary is just to perform pressure reduction control by making it lower than internal pressure P0. When the pressure reduction control is changed to the pressure increase control, the pressure increase control may be performed by increasing the pressure P1 of the accumulator higher than the internal pressure of the cylinder 2 after the pressure reduction control.

( Fifth Embodiment) FIG. 11 shows a fifth embodiment of the present invention. This embodiment is also a one-system device that performs a boost control and a depressurization control. As shown in FIG. 11, an oil passage 33 between the oil amount of the cylinder 2 and the tank 32 has a two-port two-position The on-off valves 9 and 10 are interposed in series, the accumulator 12 is connected between the on-off valves 9 and 10 by an oil passage 34, the third on-off valve 11 is interposed in the oil passage 34, and the accumulator 12 The hydraulic pump 8 is connected to the oil passage 35.

[0024] In this control device, when the step-up control, cylinder pressure P2 of the Accu over arm Correlator 12 2 inner pressure P0
Then, the valves 9 and 10 are opened and closed in the order shown in FIG. That is, when the on-off valve 11 is opened, the pressure oil in the accumulator 12 is supplied to the oil passage between the on-off valves 9 and 10 and held at the pressure of P2, and then the on-off valve 9 is opened.
The pressure oil at the pressure P2 is supplied into the cylinder 2 and the cylinder 2
Can be increased, or the stroke of the piston body 1 can be changed in the extension direction.

[0025] The case for reducing the pressure control, Accu-over-time regulator 12
Pressure P2 is set lower than the cylinder 2 internal pressure P0.
The on-off valves 9, 10, and 11 are opened and closed in the order shown in FIG. That is, the on-off valve 11 is opened to supply the pressure oil in the accumulator 12 between the on-off valves 9 and 10 to maintain the state of the pressure P2. Then, when the on-off valve 9 is opened, the internal pressure P0 of the cylinder 2 is higher than the inter-valve pressure P2, so the pressure oil in the cylinder 2 flows into the oil passage between the on-off valves 9 and 10 due to the differential pressure (P0-P2). The internal pressure P0 of the cylinder 2 decreases, or the stroke of the piston body 1 can be changed in the decreasing direction. Next, when the on-off valve 10 is opened, the pressure oil between the on-off valves 9 and 10 is discharged to the tank.

When the internal pressure of the cylinder 2 is controlled to be constant by switching between the pressure increasing control and the pressure decreasing control as needed, for example, when changing from the pressure increasing control to the pressure decreasing control, after the pressure increasing control is performed, the pressure P1 of the accumulator is increased. What is necessary is just to perform pressure reduction control by making it lower than internal pressure P0. When the pressure reduction control is changed to the pressure increase control, the pressure increase control may be performed by increasing the pressure P1 of the accumulator higher than the internal pressure of the cylinder 2 after the pressure reduction control.

( Sixth Embodiment) FIG. 14 shows a sixth embodiment of the present invention. The said
In the fourth and fifth embodiments, the pressure of the accumulators 6 and 12 is controlled to be higher or lower each time the pressure is increased or decreased, but it is possible to eliminate the trouble of adjusting the pressure. FIG. 14 shows an example of such a control device, in which an open / close valve 4 and a switching valve 15 are interposed in an oil passage connected to the cylinder 2, and a high pressure accumulator is provided in an oil passage 37 at a port a of the switching valve 15. 6 is connected, and an on-off valve 20 is interposed in the middle of the oil passage 37. The port b of the switching valve 15 is connected to the oil passage 36 and the tank 32.
It is connected to the. The accumulator 12 for low pressure is connected by an oil passage 38 between the on-off valve 20 and the switching valve 15 of the oil passage 37, and the a port of the three-port three-position switching valve 23 is connected in the middle of the oil passage 38. I have. The b port of this switching valve 23 is connected to an oil passage 39
At the tank 32. The on-off valve 20 and the switching valve 23 constitute a flow path selection mechanism described in claims. An oil passage 41 is connected to the high-pressure accumulator 6, and an oil passage 42 is connected to the low-pressure accumulator 12. The oil passages 41 and 42 are selectively connected to the hydraulic pump 8 by a three-port two-position switching valve 22.

In this embodiment, when the switching valve 22 is at the position I shown in the figure, the pressure oil can be supplied to the low-pressure accumulator 12 and when the switching valve 22 is switched to the position II, the pressure oil can be supplied to the high-pressure accumulator 6. Of course, the pressures P1, P2 of the accumulators 6, 12 can be set to desired values by the detection values of the pressure detectors 7, 13.

In the case of boost control in this embodiment, when the switching valve 23 is in the neutral position and the on-off valve 20 is opened,
Since the high-pressure oil of the accumulator 6 can be supplied to the port a of the switching valve 15, the neutral position of the switching valve 15 as shown in FIG.
By switching between the positions and opening and closing the on-off valve 4, the second position in FIG.
The boost control can be performed similarly to the embodiment. Further, when the switching valve 23 is switched to the position I while the on-off valve 20 is in the closed position, the low-pressure oil of the accumulator 12 can be supplied to the port a of the switching valve 15, so that the switching valve 15 shown in FIG. The depressurization control can be performed by switching between the position, the II position, and the neutral position, and opening and closing the on-off valve 4, similarly to the second embodiment in FIG.

( Seventh Embodiment) FIG. 15 shows a seventh embodiment of the present invention. This embodiment is also an embodiment in which the trouble of adjusting the pressure of the accumulator is eliminated. As shown in FIG. 15, on-off valves 9 and 10 are provided in series in an oil passage 33 between the oil chamber of the cylinder 2 and the tank 32, and a high-pressure passage between the on-off valves 9 and 10 is provided by an oil passage 34. The on-off valve 20 is interposed in the oil passage 34 and connected to the accumulator 6. The accumulator 12 for low pressure is connected to the downstream of the on-off valve 20 via an oil passage 42, and the on-off valve 21 is interposed in the oil passage 42. The on-off valve 20 and the switching valve 21 constitute a flow path selecting mechanism described in claims.
The two accumulators 6 and 12 are connected to oil passages 41 and 42, respectively, and are selectively connected to the hydraulic pump 8 by a switching valve 22 interposed in the oil passages 41 and 42. ing. Also in this embodiment, the two accumulators 6 and 12 can be set to a desired pressure while detecting with the pressure detectors 7 and 13.

Then, the on-off valve 21 is set to the closed position, and
When the valve is opened, the high-pressure oil of the accumulator 6 can be supplied between the on-off valves 9 and 10 interposed in series.
By opening and closing as shown in FIG. 12, the boost control shown in FIG. 3 can be performed. If the on-off valve 20 is closed and the on-off valve 21 is opened, the low-pressure oil of the accumulator 12 can be supplied between the on-off valves 9 and 10 interposed in series. 6A and 6B by opening and closing as shown in FIG.
Can be performed. As described above, in the present embodiment, since the accumulator dedicated to high pressure and low pressure is used,
There is an advantage that both the pressure increase control and the pressure reduction control can be performed only by switching the on-off valves 20 and 21.

[0032]

According to the invention of claim 1 according to the present invention, since they have a pressure generating unit for generating a predetermined pressure between the valve, the oil
It is possible up control and the pressure control of the pressure device, and controls the supply and discharge of pressure oil by a pressure difference between the hydraulic machine <br/> device and Benkan volume, follow with respect to the target pattern of the pressure and stroke accuracy Can be greatly improved. Claim 3
According to the invention, since the step-up control and the step-down control are performed by independent control open circuits, there is an advantage that the step-up and step-down switching can be performed quickly. According to the fourth and fifth aspects of the present invention, the pressure of the accumulator is adjusted while being a single system device.
Both boost control and decompression control can be performed. According to the sixth and seventh aspects of the present invention, the connection between the high-pressure accumulator and the low-pressure accumulator is selected by the flow path selection mechanism, so that the pressure increase control and the pressure reduction control can be performed without adjusting the pressure of the accumulator.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a boost control device according to a first embodiment of the present invention.

FIG. 2 is a time chart of an opening / closing valve operation of the boosting operation follow-up control device.

FIG. 3 is a time pressure diagram in the tracking control device for boosting operation.

4 is a hydraulic circuit diagram in our Keru depressurization operation for tracking control apparatus according to a second embodiment of the present invention.

FIG. 5 is a time chart of an opening / closing valve operation of the pressure reduction operation following control device.

FIG. 6 is a time pressure diagram in the tracking control device for pressure reduction operation.

FIG. 7 is a hydraulic circuit diagram of a tracking control device according to a third embodiment of the present invention.

FIG. 8 is a hydraulic circuit diagram of a tracking control device according to a fourth embodiment of the present invention.

FIG. 9 is a time chart of the on-off valve operation of the boosting operation in the tracking control device.

FIG. 10 is a time chart of an opening / closing valve operation of a pressure reducing operation in the tracking control device.

FIG. 11 is a hydraulic circuit diagram of a tracking control device according to a fifth embodiment of the present invention.

FIG. 12 is a time chart of an opening / closing valve operation of a boosting operation in the tracking control device.

FIG. 13 is a time chart of an opening / closing valve operation of a pressure reducing operation in the tracking control device.

FIG. 14 is a hydraulic circuit diagram of a follow-up control device according to a sixth embodiment of the present invention.

FIG. 15 is a hydraulic circuit diagram of a tracking control device according to a seventh embodiment of the present invention.

FIG. 16 is an explanatory diagram of an ultra-high pressure generator to which the present invention is applied.

FIG. 17 is a time pressure (stroke) diagram showing the operation of the tracking control device of the present invention.

FIG. 18 is an explanatory diagram of control accuracy of the tracking control device of the present invention.

FIG. 19 is a hydraulic circuit diagram of a conventional tracking control device.

[Explanation of symbols]

Reference Signs List 1 piston body 2 cylinder 3 pressure detector 4 on-off valve 5 on-off valve 6 accumulator (for high pressure) 7 pressure detector 8 hydraulic pump 9 on-off valve 10 on-off valve 11 on-off valve 12 accumulator (for low pressure) 13 pressure detector 14 position detection Switch 15 Switching valve 20 Switching valve 21 Switching valve 22 Switching valve 23 Switching valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F15B 9/09 F15B 11/028

Claims (7)

(57) [Claims] 1. A follow-up operation control device for causing an internal pressure or a stroke of a hydraulic device to follow a target pattern, wherein the control device is sequentially interposed in a flow path connected to an oil chamber of the hydraulic device.
Check valve, first on-off valve, second on-off valve, accumulator
Data, a hydraulic pump, and a position detector for detecting a stroke of the hydraulic device or
A pressure detector that detects a pressure in an oil chamber of the hydraulic device, a pressure detector that detects a pressure of the accumulator, a position detector or a pressure detector of the hydraulic device, and
Based on the detection data of the accumulator pressure detector,
Driving the hydraulic pump and opening and closing the first and second on-off valves
A control device for controlling the operation, the pressure of the accumulator is calculated from the pressure of the hydraulic equipment
Is slightly higher, and the first on-off valve is closed.
Then, the second on-off valve is opened, and the flow path between the first and second on-off valves is opened.
The internal pressure is made higher than that of the hydraulic equipment, and then the second on-off valve
And open the first on-off valve to open the oil chamber of the hydraulic equipment.
Supply a slightly higher pressure and repeat this cycle
This allows the pressure to follow the target pressure for an extremely long time.
A follow-up operation control device for a hydraulic device, characterized in that: 2. A follow-up operation control device for causing an internal pressure or a stroke of a hydraulic device to follow a target pattern, the control device being sequentially interposed in a flow path connected to an oil chamber of the hydraulic device.
A first on-off valve, an accumulator, a second on-off valve,
An accumulator is interposed in the connection oil passage connecting the flow passage.
Hydraulic pump for supplying a third on-off valve, the hydraulic oil in the accumulator which is
And a position detector for detecting the stroke of the hydraulic device or
A pressure detector for detecting the pressure of the oil chamber of the hydraulic equipment, a pressure detector for detecting the pressure of the accumulator, the position detector or a pressure detector, and the A of the hydraulic equipment
Based on the detection data of the pressure detector
Driving the hydraulic pump and opening the first, second, and third on-off valves
A control device for controlling the closing operation , wherein the pressure of the accumulator is also known as the pressure of the hydraulic device.
In a state where the first and second on-off valves are closed shortly
Then, the third on-off valve is opened to open the flow path between the first and second on-off valves.
The pressure is lower than that of the hydraulic equipment, and then the first on-off valve is
Open the valve and slightly discharge the oil pressure from the oil chamber of the hydraulic equipment,
By repeating this cycle, the eye can be
A tracking operation control device for hydraulic equipment, characterized in that the pressure tracking is performed to a standard value . 3. An internal pressure or stroke of a hydraulic device is set to a target value.
A follow-up operation control device for following a turn.
I, wherein the first flow path connected to the hydraulic equipment, and two on-off valves, a boost operation control apparatus interposed pressure generating portion consisting of an accumulator connected to the pump in this order, the oil
The second flow path connected to the pressure device, connecting the two closing valves in series, between the two on-off valve, the third on-off valve the pressure generating portion consisting of an accumulator connected to the pump A follow-up operation control device for a hydraulic device , comprising: a pressure-reduction operation control device connected through a connection. 4. An internal pressure or stroke of a hydraulic device is set to a target value.
A follow-up operation control device for following a turn.
I, the opening and closing valve and the third port 3-position switching valve which is interposed in this order to a connected flow paths to the hydraulic equipment, and an accumulator connected to one port of the switching valve, which is connected to the other port A tank, a pump connected to the accumulator, and a position detector for detecting a stroke of the hydraulic device or
A pressure detector for detecting the pressure of the oil chamber of the hydraulic equipment, a pressure detector for detecting the pressure of the accumulator, the position detector or a pressure detector, and the A of the hydraulic equipment
Based on the detection data of the pressure detector
Driving of the hydraulic pump and opening and closing of the on-off valve and the switching valve
A control device for controlling the operation, the pressure of the accumulator is calculated from the pressure of the hydraulic equipment
To a slightly higher level and supply it to the oil chamber of the hydraulic equipment.
Control the boosting operation, and adjust the pressure of the accumulator to the
Keep the hydraulic pressure slightly lower than the hydraulic
A follow-up operation control device for a hydraulic device , wherein the device performs a pressure reduction operation by discharging the oil from an oil chamber of the device. 5. An internal pressure or stroke of a hydraulic device is set to a target value.
A follow-up operation control device for following a turn.
Thus, in the flow path connected to the oil chamber of the hydraulic device,
The first on-off valve, the accumulator, the second on-off valve and the
The accumulator is interposed in a connecting oil passage connecting the
Hydraulic valve for supplying hydraulic oil to the accumulator
And a position detector for detecting the stroke of the hydraulic device or
A pressure detector for detecting a pressure in an oil chamber of the hydraulic device, a pressure detector for detecting a pressure of the accumulator, a position detector or a pressure detector for the hydraulic device, and the pressure detector.
Based on the detection data of the pressure detector
Driving the hydraulic pump and opening the first, second, and third on-off valves
A control device for controlling the closing operation , wherein the pressure of the accumulator is calculated from the pressure of the hydraulic device.
To a slightly higher level and supply it to the oil chamber of the hydraulic equipment.
Control the boosting operation, and adjust the pressure of the accumulator to the
Keep the hydraulic pressure slightly lower than the hydraulic
A follow-up operation control device for a hydraulic device , wherein the device performs a pressure reduction operation by discharging the oil from an oil chamber of the device. Flow and wherein said 3-port three-position high pressure pressure generation unit to one port of the switching valve consists of a high-pressure accumulator which is connected to pump, and a low-pressure pressure generating unit comprising a low-pressure accumulator connected to the pump 5. The tracking operation control device according to claim 4 , wherein the switching operation is selectively performed via a path selection mechanism, and another port of the switching valve is connected to a tank. 7. A high-pressure pressure generator comprising a high-pressure accumulator having a pump connected to a flow passage between the first and second on-off valves, and a low-pressure pressure generator comprising a low-pressure accumulator having a pump connected thereto. 6. The follow-up operation control device according to claim 5, wherein the control device is selectively connected via a flow path selection mechanism.